Sheet clamping device



Mmwh F. W. STORCK ET AL SHEET CLAMPING DEVICE Filed April 24,

1945 2 Sheets-Sheet l 1 3947 F. w. smwcx ETAL CIJAJMPING' DEVICE 2 sheets shee't 2 Filed April 24, 1.943

[mill] llllllllllll II III IIIIIHI Patented Mar. 18, 1947 SHEET CLAMPING DEVICE Frederick W. Storck, Arlington, and Paul T.

Trueman, Canton, Mass., assignors to Standard Duplicating Machines Corporation, Everett, Mass, a corporation of Massachusetts Application April 24, 1943, Serial No. 484,388

2 Claims.

This invention relates to duplicating machines of the character wherein a master copy sheet is secured to a rotatable drum and clear moistened sheets are engaged under pressure with the master copy sheet. More specifically, the invention is directed to novel means for actuating a clamping device that is effective to secure the master copy sheet to the drum.

For efficient operation of a machine provided for the duplicating from a master sheet, the means for securing the master to the rotatable drum of the machine should be preferably arranged so that the master can be attached to and released from the drum expeditiously. In duplicating machines it has been the general practice to utilize some form of clamping means associated with the peripheral face of the drum with various instrumentalities for actuating the clamping means tosecure and release the master copy relative to the drum. Many such devices have required a multiplicity of elements that in instances require the inconvenient mounting of many of the functionalparts within the drum.

Accordingly, one of the primary objects of the present invention is to provide a master clamp actuating device with few working parts that may be readily assembled to function in an efficient manner.

Another object of the invention is to provide and arrange instrumentalities in association with the drum and in a manner that will automatically operate to receive and/or release the master copy at a determinate stopping point in the cycle of rotative movement of the drum.

The foregoing objects are intended as a general explanation and are not to be construed as limiting the invention thereto as further objects and advantages of the instrumentalities will become obvious from the following description of a preferred form and embodiment of the invention as illustrated in the drawings forming a part hereof.

Fig. 1 is a vertical transverse section of a duplicating machine having the elements of the present invention embodied therewith.

Fig. 2 is a plan view of Fig. 1 but in this plan view some of the machine parts are omitted.

Fig. 3 is a transverse section taken substantially along line 33, Fig. 2.

Fig. 4 is a view corresponding to Fig. 3 but shows the parts in a different position.

Fig. 5 is a detail of the clampactuating lever.

, 6 is a detailof the locking dog or lever.

Fig. *7 is a detail of a modified form of clamp actuating lever, and

Fig. 8 is a detail of a modified form of locking dog or lever.

The duplicating machine For the purpose of illustrating a practical embodiment of the invention, the duplicating machine in the present instance is provided with opposed side frames Ill, only one of which is shown. The printing drum ll of the machine is rotatably mounted on a shaft l2 suitably journalled in the opposed side frames [0. A longitudinally extending sheet receiving slot i3 is provided in the face of the drum and this slot l3 has apertures I 4 connecting therewith that extend into the drum interior.

Clear sheets (not shown) are fed from the sheet stack support l5 to the combined feeding and moistening rollers I6, I! that are rotated in relation to the movement of the drum by suitable gearing such as a gear l8, disposed to rotate the lower feed and moistening roller 16, and an intermediate gear I!) that meshes with the roller gear l8 and a drive gear 20 rotatable with the drum H. The roller I! is rotated by frictional contact with the driven roller l6.

As the rollers l6, I1 are rotated, the moistening device 2| applies moisture to the face of the lower moistening roller l6 and, as the sheet is advanced by the rollers l6, ll, this moisture is transferred to the face of the clear sheet.- Continued rotation of the rollers l6, ll feeds the clear moistened sheet into the bight formed by the drum 1 I and its coacting pressure roller 22 so that the rotative movement of the drum will advance the sheet under pressure into engagement with the master copy sheet A and thereby produce a duplicate copy of the master on the moistened clear sheet.

The drum ll may be intermittently rotated in its printing direction, as indicated by the arrow, Fig. 1, by manual means or a suitable source of power and mechanism (not shown) and, further, the rotative direction of the drum may be reversed, in the direction of the arrows Figs. 3 and 4, for purposes that are presently set forth.

A complete description of a duplicating machine of the above character, together with its method of operation, is contained in Reissue Patent No. 19,951 issued April 28, 1936, to Frederick W. Storck; therefore further detailed description of the machine is thought to be unnecessary.

The master sheet clamp The instrumentalities of the clamping device include, in this instance, a plurality of fingers 23 that are preferably resilient in character. These fingers 23 are attached to a shaft 24 disposed in the interior of the drum and rockably supported by suitable bearings in the opposed end Walls of the drum. The outer terminating end portions of the fingers 23 project into the drum apertures I4 and are adapted to be operatively engaged with one side wall of the sheet. receiving slot l3 in a manner to clamp an edge.

of the master copy sheet therein as illustrated at Fig. 1.

Secured to an outwardly extending end of the clamp shaft 24 is a clamp shaft actuating lever 25. This actuating lever 25 is provided with a bore 25h, see Fig. 5, adapted to receive a sliding shoe 25 that is urged outwardly by a compression spring 21 disposed in the bore 25h of the lever 25. When in assembled relation, the shoe 26 has its bearing against a collar 28 mounted on the drum shaft l2, see Figs. 1 and 3. Through the action of the compression spring 21 the clamp actuating lever 25 is urged in a contra-clockwise direction and thus the clamp fingers 23 are forced into operative engagement with the sheet and receiving slot l3 and the shoe 26 projects from the lever 25 in a manner that permits this lever 25 to be rocked in a contra-clockwise direction. A stop lever 29is disposed in the rotative path of the clamp actuating lever 25 and this stop lever 29 is rockably supported on a pivot 30 fixed in the side frame. In the present arrangement of the instrumentalities, the stop lever 29 is provided with an angular end face 29a that is disposed to engage with a hub I la of the side frame H in a manner that limits the rotative movement of the stop lever 29 in a clockwise direction and thus positions the lever 29 for operative engagement with the clamp actuating lever 25 when the master copy sheet A is to be released from the drum ll.

Operation When functionally operating the machine, a master copy sheet A is secured to the drum ll, Fig. 1, and the drum is rotated in its printing direction, asindicated by the arrow, the angular end faces 25a, 25b of the clamp actuating lever 25 will engage with the under face 292) of the stop lever 29 and cause this lever 29b to be inoperatively rocked in a contra-clockwise direction, see Fig. 3, at each cycle of rotation of the drum.

When it is desired to release and remove the master copy sheet A from the drum, the drum It is rotated in a contra-clockwise direction as indicated by the arrow, Fig. 4. During this rotative movement of the drum II, the end face 250 of the clamp actuating lever 25 will first engage with an angular face 290 of a projecting portion 29d, of the stop lever 29. Continued rotation of the drum II will cause the cam actuating lever face25c to slide up on the stop lever face 290, thereby rocking the lever-25 to the right against the pressure of the slidable shoe spring thus opening the clamp fingers 23 from the operative engagement with the slot [3. During the rocking movement of the clamp actuating lever 25, the face 250 of this lever will continue to slide up on the coacting end face 290 of the lever 29 until the projecting portion 29d, of the stop lever 29, enters a-notch 25a in the actuating lever 25 and its face 250 engages with the end face see of the stop lever'z's to arrest further 4 rotation of the drum in its contra-clockwise direction.

Preferably, the faces 25g, 29g of the levers 25, 29 are angularly disposed when operatively engaged and urged so as to provide a latching action affected by the disposition of the faces and the pressure of the sliding shoe spring 21 in urging the faces 25g, 29g into close engagement so as to overcome any back-lash movement of the drum against the pressure spring 21 with an attendant displacement of the coacting levers 25, 29 from their locking and clamp opening positions.

Modification Fig. 7 illustrates a simplified form of clamp actuating lever 35 that may be used to rock the clamp shaft [2. This lever 35 is also provided with a bearing shoe 26 as previously described, but is not provided with a notched portion 25a. The coacting stop lever 36 is provided with an angular end face 36a that is adapted to engage with the hub Ila of the side frame II in a manner that will limit the rotative movement of the lever 36 in a clockwise direction when these modified elements are operatively assembled in place of the levers 25-, 29 previously described.

With these modified elements 35, 36 disposed in operative relation, when the drum is rotated in its functionally operative direction, as indicated by the arrow Fig. 1, the angular end face 3512 will engage the under face 361) and cause this lever 35 to be inoperatively rocked in a contraclockwise direction.

To release the clamping device, the drum II is rotated in a contra-clockwise direction as above described. During this rotative movement of the drum, the under face 35c of the clamp actuating lever 35 will engage with an angular face 36e of the stop lever 35. Continued rotation of the drum II will cause the cam actuating lever face to slide up on the angular stop lever face 36c, thereby rocking the clamp lever 35 to the right thus opening the clamp fingers 23 and simultaneously arresting rotative movement of the drum in its contra-clockwise direction.

While the form and arrangement of parts as shown in the, drawings and as above described are preferred, the invention is not to be limited to such form and arrangement except so far as the claims may be so limited, it being understood that changes might Well be made in the form and arrangementol' the parts by those skilled in the art without departing from the spirit and'scope of the invention and in which it is the intention to claim all novelty inherent in the invention as broadly as possible, in view of the prior art.

What we claim is:

1. A device of the character specified having a revolvable printing platen with means for r0- tating said platen and means for clamping one edge of a master copy sheet to the printing platen, said clamping means including a sheet edge receiving guide associated with the face of the platen, together with sheet edge clamping instrumentalities carried by the platen and having opposed operative and inoperative positions with means. foractua-ting said instrumentalities, said last means including varockable lever carried by the platen and associated with said clamping instrumentalities, with pressure means urging said instrumentalities into their operative position, a-pivoted lever-fixed in the rotative path of said rockable lever, each of said levers having angularly disposed fa'ces, together with opposed male and' female portions adapted for engagemeat with one another when said platen is rotated in one direction and whereby rotative movement of said drum in that direction is arrested and said clamping instrumentalities are actuated to their inoperative position against the action of said pressure means and said male and female portions havingengaged latching faces disposed to retard movement of the platen in an opposite direction.

2. A device of the character specified having a revolvable printing platen with means for rotating said platen and means for clamping one edge of a master copy sheet to the printing platen, said clamping means including a sheet edge receiving guide associated with the face of the platen, together with sheet edge clamping instrumentalities carried by the platen and having opposed operative and inoperative positions with means for actuating said instrumentalities, said last means including a rockable lever carried by the platen and associated with said clamping instrumentalities, with pressure means urging said instrumentalities into their operative position, a pivoted lever fixed in the rotative path 6 of said rockable lever, said levers being provided with contact faces adapted for engagement with one another when said platen is rotated in one direction and whereby rotative movement of said drum in that direction is arrested and said clamping instrumentalities are actuated to their inoperative position against the action of said pressure means and said male and female portions having engaged latching faces disposed to retard movement of the platen in an opposite direction.

FREDERICK W. STORCK. PAUL T. TRUEMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 20,753 Ritzerfeld June '7, 1938 2,083,044 Storck June 8, 1937 2,093,385 Storck Sept. 14, 1937 2,117,165 Hernlund May 10, 1938 

